Chain grate stoker



Nov. 17, 1931. c. J. HANIMAN CHAIN GRATE. STOKER- Filed June25, 1925 3 Sheets-Sheet 1 I.IINVENTORI 7L1. M- j ATTORN EY Nov. 17,- 1931. c. J. HANIMAN 1,832,459

CHAIN GRATESTOKER I Filed June 25, 1925 a Sheegs-Sheec 2 ATTORNEYJ Nov. 17, 1 931. c. J. HA'NEK CHAIN GRATE STOKER Filed June 25, 1925 3 Sheets-Sheet 3 ATTORNEYS Patented Nov. 17, 1931 UNITED STATES PATENT OFFICE CHARLES :r. or BAYONNE, NEW messy, assmnon TO HE nnoocx awn.-

cox comm, or Baron-E, new JERSEY, a comoiwnon or NEW mnsmr CHAIN GBATE STOKER Application filed June as, 192's.v Serial No, 39,408.

My present invention relates to chain grate stokers, and particularly to such stokers in" which the combustion air is fed to the fuel through air boxes located between the runs of the grate, and will be best understood from the following description and the annexed drawings in which Fig. 1 is a side sectional eliation of a chain grate to which my invention has been applied; Fig. 1 is a side view.

mechanism and the draft boxes with the ash handling equipment between the runs of the grate; Fig. 3 is'an enlarged side elevation,

' partly in-section, of some of the mechanism shown in Fig. '1;F-ig.'-4 is an end view of the plan view of parts shown in Fig. 6.

so ried on sprocket wheels 11, 12, the latter be-- parts shown in Fig. 3, with some of the parts insection; Fig. 51s a plan view of the parts the chain 10 to the fuel bed also permit siftings from the fuel to fall downward into the air boxes and, unless such siftings are removed, the air' boxes would soon become clogged and prevent the inflow of the combustion air. a

In. the specific form of air box, which I have illustrated, openings are provided in the bottom of each air box extending across the width of the grate, each of these openingsbeing controlled by an oscillating flap valve which is normally closed. Since these flap valves are the same for each opening, it will be understood that a description of one will apply to all of the others. V a Above the openingin the air box extends a shaft 24 which preferably is made square and on which is a flap valve having wings 25 and 26 extending from opposite sides of the shown in Fig. 3;,Fig. t'pis a separate-view f s The g 25 is formedto rest of a detail'shown in. Fig. 3, bein a section taken on line 6'6 of Fig. 7, and ig. 7 is a Like reference characters indicate like parts throughout the drawings.

In the illustrative embodiment shown in the drawings, I have chosen for purposes of illustration a well-known form of chain grate in which the chains 10'of the grate are caring connected to a driven shaft 13, driven by a motor 14 through a worm gear 15 on a shaft 16,- the shaft'16 carrying a worm 17 meshingwith a worm gear 18 on the shaft 13, so that 14 may be a high-speed motor and through the reduction gearing, the chain 10 will be moved slowly to carry the fuel from the. fuel hopper through the combustion chamber. 'Smce' the specific form of chain grate is not part of my present invention, further descrlption thereof will be unnecessa to those skilled in the art. a

the form of grate illustrated, air under pressure is supplied to the fuel on the grate through air boxe's19, 20 and 21, the air entering such boxes through ducts 22 connected to an air supply duct 23,'all in the usual manner;

- The 0 nings through which the air from the air xes finds its way upward through shaft 24 is turned in a-clockwise direction in Fig. 1, it will be obvious that the wing 25 will rise from its seat and permit any sittings accumulated aboveit in the-air box to be blown out by the air pressure onto the lower run of the chain 10, such siftings finding their way' through the openings in the chain into hoppers 28. By reason of the arc-shaped portion 27-, however, the turning of the shaft "21 will not. open thevalve on that side. This arrangement is provided so that the valve will remain more nearly air tight than if this arcshaped portion were not provided. Preferably the wing 25 is made slightly larger in area than the wing 26,.so that the air pressure in the air box will tend to hold the win 25 closed on its seat to prevent air leakage an the arc-shaped portions serve to seal the other Side of the valve. Furthermore, this arcshaped portion minimizes the possibility of large pieces of sittings remaining on the valve to prevent itsclosing. If the wing 26 were made to contact with a valve seat cooperating with its upper portion, it would be possible for some of the siftings to lodge between the wing 26 and such seat when the shaft 24 is turned counterclockwise close the opening.

It will be noted that I have provided, in the illustrative embodiment, a pair of 0 enings each controlled by a fla valve sue as just described. Preferably, arrange these valves so that when the shaft 24 is turned clockwise, as seen in Fig. 1, the wing 26 will be sloping in a downward direction, so that siftings collected thereon will slide through the opening at the right-hand side of the air box produced by the tilting of valve onthat side. If desired, the valves may be provided with projections 29 which will stir up the accumulated siftings in the air box at each oscillation of the shafts 24. Projection 29 also acts as a web reinforcement to strengthen the air valve longitudinally.

It will be obvious that if the valves controlling the openings from the air boxes remain open for any considerable length of time, there would be a loss of the air under pressure and also a disturbance of the air supply to the fuel. To avoid this, I have provided mechanism by which the valves may be opened automatically but in such a manner that they will remain open for only a short time; Furthermore, 1 preferably provide mechanism by which these valves are opened automatically at predetermined intervals, the space between such intervals being relatively long and, of course, in accordance with the rapidity of accumulation of siftings in the boxes.

In the illustrative embodiment, eagh shaft 24 is provided at its end with a lever 30 haw ing a cam roller 31 engaging the groove in a cam 32 connected to a shaft 33, the groove in the cam 32 being arranged so that when the shaft 33 is given a single rotation, the lever 30 will be given one complete oscillation, and consequently the valves opened and closed.

On the end of-shaft 33 and loosely mounted thereon, are the cooperating positive clutch members 34 and 36, provided with the usual clutch teeth, member 34 being driven from shaft 16 through chain'35.

Shaft 33 is to be given one rotation only for each cycle, and the following mechanism is provided so that the shaft may be started when desired and stopped at the end of one rotation.

The hub of clutch member 36 is provided with a spiral groove 37. As shown in Fig. 3, thisis in the nature of a screw thread, but of slightly less than 360 in length. It will be obvious that, if a pin, as 38, is held in this groove as the member '36 rotates, the member 36 will be given an endwise movement if pin 38 cannot move endwise. It will also be obvious that, so long as pin 38 is in groove 37, in the position shown in Fig. 3, member 36 cannot rotate in the direction of the arrow (the direction in which the constantly running member 34 tends to rotate shaft 33) bewhich, in turn, is fastened to shaft 40. The 7 weight of lever 44 attached 'to shaft 40 (for a purpose to be described later) aided, if desired, by a spring 39, gives a counter-clockwise (as viewed in Fig. 3) bias to lever 39. This tends to maintain pin 38 in the position shown in Figs. 3 and 4, with pin 38 in groove 37.

Splined to shaft 33 is a driving member 41, the splined connection permitting movement of member 41 axially of shaft 33, while holding it against rotation on shaft 33. The hub of clutch member 36 is extended (with a relatively small diameter inside of spring 43, which springwill be described hereinafter) into contact with driving member 41, spring 42, abutting against a bearing for shaft 33, biasing driving member 41 and clutch member 36 towards the left in Fig. 3, the pin 38 (when in the positions of Figs. 3 and 4) preventing any motion, however, in this direction.

A yielding driving connection between member 36 and member 41 is provided by the helical spring 43, surrounding that part of the hub of member 36 which has the reduced diameter, and having one end entered in a hole in the hub of member 36 and the other end in a hole in member 41. Spring 43 constitutes one of several well-known forms of yielding and shgck-absorbing driving connections betwen rotating parts, which may be used to transmit rotation from member 36 to member 41.

To the shaft 40 is connected a lever 44, which, in turn, is connected to a bell crank 45, connected, in turn, to a bell crank 46, the free end or toe portion 47 of which is arranged to be struck by the end of an arm 48 provided with a weight 49 and freely mounted on a fixed stud 50. The stud 50 is provided with a worm wheel 51, driven by a worm 52 on .the shaft 16, the worm wheel 51 having a projection 53 turning in the plane of the arm 48. A handle 54 is connected to the bell crank 45 to permit a manual disengagement of pin 38 from the groove in the clutch member 36 to secure extra ash dumping movement.

With the parts in the position shown in Fig. 3, the rotation of the shaft 16, as the chain grate is in operation, will turn the worm gear 51 counterclockwise in Fig. 3, the projection 53 engaging the arm 48 to lift it to a vertical position. As soon as the arm 48 has reached the position 48 in Fig. 6, it will fall by gravity to the full-line position in that figure and will strike the arm 4'. to turn it to the dotted-line position of Fig. 6. This will rotate the shaft 40 clockwise in Fig. 4 and will withdraw the pin 38 f1 om the groove 37 The spring 42 now moves the clutch member 36 to the left in Fig. 3 to cause the lull clutch teeth thereon to engage with the clutch teeth of the member 34 w ich is bein I turned through the chain 35 from the s aft 16.

The clutch member 36 now begins to turn and transmits its motion through the spring 43 to the member 41 and consequently to the shaft 33, so that the cams 32 begin to rotate to oscillate the shafts 24.

As arm 46, 47 is swung downward by arm 48, the latter passes the former and moves to position 48" of Fig. 6. Arm 46 is now free to return to its full line position of Fig. 6 and pin 38 is therefore again biased counterclockwise in Fig. 4, by the weight of lever 44 and the pull of spring 39. The longitudinal movement of member 36 to the left of Fig. 3, and its partial rotation while pin 38 is out, of groove 37, has brought the other end of groove 37 opposite pin 38, which now again enters groove 37. ,As the member 36 continues ,to turn, the pin 38 acts on the groove to cam the clutch member 36 to the right in Fig. 3 to draw the clutch teeth out of engagement, which occurs when the shaft 33 has made one complete turn and the shaft 33 is again brought to rest with the parts in the position shown in Fig. 3. The complete rotation of the shaft 33 will have caused a complete oscillation of the shafts 24 and a consequent quick opening and closing of the valves in the air boxes. The spring 43 is provided to take up any shock due to the sudden starting of the clutch member 36 lwhen its teeth engage with the clutch mem- It is obvious that the intervals between- I its driving worm, I mount it upon a supporting bracket 55 adjustably positioned upon the main frame 56' of the grate. A slot 57 is provided in each arm of the bracket 55 to provide for sliding the bracket 55 vertically when the attaching bolts in slots 57 are loosened. At any change of the worm gear 51, the bracket 55 may be moved vertically on its bolts to accommodate the size of the gear and cause the stud 50 to retain the gear meshing properly with the worm. For instance, a larger gear would necessitate a downward movement of the bracket and would cause a relatively larger time interval between operations of the shaft 33 amid the ash handling valves 25.

a The handle 54 provides a convenient means by which the shaft 33 may be coupled to the driving power through clutch 36 to be rotated at the will of the operator if, for any reason, the siftings are accumulating in the air boxes faster thanthe automatic set- ,charged, a valve for said opening operating means including a clutch between ting of the parts will take care of. This performs a movement which withdraws the pin 38 from the clutch 36 releasing it to perv:

mit a rotation of shaft 33 and a rocking of the shafts 24 with their associated valves to dump ashes from the air boxes.

It will be understood that the arrangement which I have shown is merely illustrative and that the embodiment of my inven- 'to drive said grate, a wind box below the upper run of the grate and having an opening through which fuel siftings may be discharged, a valve for said opening, valve-opcrating means disconnectable from the grate driving means, and timing means to connect and disconnect said valve-operating means to the grate-driving means at predetermined intervals in the travel of the grate, said valveoperating means being arranged to be operated by hand by the operator independent of said timing means.

3. In combination, a chain grate, means to drive said grate, a wind box below the upper run of the grate and having an opening through which fuel siftings may be discharged, a valve for said opening, valve-operating means disconnectable fromthe gratedriving means, and timing means to connect and disconnect said valve-operating means intervals in the travel of the grate, said valveoperating means being arranged to give the valve a relatively quick opening and closing motion.

4. In combination, a chain grate, means to drive said grate, a wind box below the upper run of the grate and having an openlng through which fuel siftings may be iiisf va vethe grate-driving means and the valve, and timing means to operate said clutch at pre- .to the grate-driving means at predetermined Ill determined intervals in the travel of the grate.

I 5. In combination, a chain grate, means to drive said grate, a wind box below the upper run of the grate and having an opening through which fuel siftings may be distiming means to operate said clutch at pre:

- charged, a valve for said opening, valve-opdetermined intervals in the travel of the grate, said timing means being arranged to open said clutch after the valve has been opened and closed.

6. In combination, a chain grate, means to drive said grate, a wind box below the upper run of the grate and having an opening through which fuel siftings may be of travel of said chain grate.-

di'scharged,'a valve to control said opening, and means independent of the grate to open and close said valve at predetermined in-v tervals and in quick time relative to the rate 7. In combination, a chain grate, a wind box below the upper run of the grate, a flap valve forming part of the bottom of the wind box pivoted between its edges, and arranged with one edge resting on a valve seat and the other edge having an arc-shaped portion cooperating with an arc-shaped portion of the wind box, whereby, when the valve is oscillated on its pivot, siftin s may fall from the wind box at one side of the valve only, and means to oscillate said valve.

8. In combination, a chain grate, a wind box below the upper run of the grate, a pair 10f flap valves forming part of the bottom of the wmd box, each of said valves comprisin a flat plate pivoted between its edges an having one of its edges e aging a valve seat and its other edge arc-shaped and cooperating with an arc-shaped-portion of the wind box to seal the last-named edge when the valve is oscillated to move the first-named edge from its seat, one of said valves being arranged to dump siftings collected thereon into the opening controlled by the other of said valves, when the valves are oscillated to open position, and means to oscillate said valves.

C ARLES J. 

